Re-implemented Backdrop Node

Nodes/group_node.py

@@ -0,0 +1,21 @@
+from OdenGraphQt import GroupNode
+
+
+class MyGroupNode(GroupNode):
+    """
+    example test group node with a in port and out port.
+    """
+
+    # set a unique node identifier.
+    __identifier__ = 'nodes.group'
+
+    # set the initial default node name.
+    NODE_NAME = 'group node'
+
+    def __init__(self):
+        super(MyGroupNode, self).__init__()
+        self.set_color(50, 8, 25)
+
+        # create input and output port.
+        self.add_input('in')
+        self.add_output('out')